1. Field of the Invention
The present invention relates to a tool holder for a drilling tool and, in particular, for an annular core bit.
2. Description of the Prior Art
Tool holder for conventional annular core bits with an inner thread, e.g., 1¼″ UNC or PIXIE, has a bit-side axial stop surface for axially supporting the core bit. A drawback of such releasable thread connections, e.g., according to U.S. Pat. No. 4,911,253, consists in laborious mounting of the core bit on the tool holder and its dismounting therefrom. Also, often, jamming of the thread connection occurs.
German Publication DE-37 44 091 discloses a tool holder for an annular core bit which permits quick mounting and dismounting of the core bit. The tool holder has an outer splined profile and two outer conical surfaces, and an inner splined profile and two inner conical surfaces.
German Publication DE-38 14 365 A1 discloses a tool holder for quick mounting and dismounting of an annular core bit having a special hollow flange with an outer thread. The tool holder is provided with a power tool-side (further tool-side) bayonet-type through-grooves, with an end-side cylindrical guide flange with radially projecting entraining pins, and with a bit-side axially spaced, outer thread axially supporting the bit via a sleeve having an inner thread cooperating with the outer thread, and bit-side axial stop surfaces.
German Publication DE-199 63 636 discloses a tool holder for quick mounting and dismounting of an annular core bit. The core bit has an end side inner splined profile and an axially spaced, hollow flange with an inner cone and an outer thread. The tool holder has an end-side outer cone, a splined profile provided on its tool side, and an axially offset outer thread which cooperates with an inner thread of a sleeve. For mounting the core bit, the splined profile of the bit holder engages in the inner splined profile of the hollow flange having an inner core and an outer thread.
An object of the present invention is a tool holder for quick mounting and dismounting of an annular core bit and adapted for use with both an annular core bit having a complementary splined profile and an annular core bit having an inner thread.